how much of that $75 gal do you loose when drip drying and using the proposed consumer still?
maybe 20%?
which is $15, to process a lb of weed…
personally, I don’t think the solvent is the expensive part here
[spends $1.20 on solvent, but requires $60 on residual solvent testing…]
I also want to point out that this seems like a weird hill to die on. Certainly whoever would come knocking on your door for distilling a few gallons of white lightning would be similarly displeased to find you extracting pot oil with methanol but maybe I’m just not familiar with your jurisdiction.
I think as long as you pay taxes on the beginning alcohol you’re allowed to distill it. I also think you’re allowed to legally have a unregistered 1 gallon moonshine still or a similar device as long as the capacity of the boiling alcohol doesn’t exceed a gallon. So theoretically, a 5 liter rotovap is legal as long as it’s filled halfway to capacity in the boiling flask/3.3 liters/1 gal. . That’s alcohol though.
6 samples were dropped off at the lab today. I ran three tests with two samples each. Had a thought, it would be interesting to see the MeOH PPM before and after step #4. Will post a write-up and lab results asap, probably a week or so.
Results are in! I wrote this up as an informal study. Looking for feedback for further discussion and edits.
Cheers!
I didn’t draw up any conclusions as it left me with more questions to be answered. My gut feel (to be tested) is that it didn’t matter if EtOH or water was used for re-hydrate in step #4, the residual MeOH differences were minimal. Given they are 50 to 100x under legal maximums (3000PPM), it would be safe to consume a few grams a day without coming close to limits. If you could take 3 grams of FECO and stay awake for 2 days, YOU GO! I’m leaning to conclude it is heat x time that will eventually lead to a Not Detectable (nd) result. Tests A & B showed a 10x drop in MeOH using the water and water/EtOH re-hydration. Test C finished at the same level but its starting point of MeOH was half that of Test A & B, probably due to extra time on the hotplate at the end of Stage #3.
So the question to answer is this - If enough time were given on the hotplate, would the MeOH go down to Not Detectable? and at what temperature. I noticed slights wiffs of hot oil evaporation or smoke coming off the oil before ending each run. That could be a problem if too hot and boiling off THC (300+ degrees). I would like to think this was over 240 degrees and decarbing any remaining THCA.
Anyone with experience to share?
Here’s the final version with concussions. Happy to take comments and discuss the finding!
2020.07-14.Extraction.rev1-03.pdf (3.4 MB)
Awesome notes. My concern is that there was no measurements take for temperature. Also, “wisps of smoke” indicates to me that you began to degas your terpenes rather than actually cooking your oil (160 c +)
I would bring the oil to 130 c and do a final ppm test
Good call. Thats a good plan. As noted, the end of the process was loose. Having a candy thermometer would be a good tool to have on hand.
I usually base a lot of my lab work of an IR laser temp gun. They aren’t the best but will give you a decent idea. Especially when you have 2 of them for good measure.
Beautiful write up
I remember a few years back I mentioned using methanol and folks went like WHAT
Yes all solvent purged and disposed well
Can and should be used if it makes the cleanest of product
Be responsible when working with anything even if it s brine.
It amazes me after all these years, there has never been a write-up or study done comparing the various solvents and the residual PPM concentrations. The closest I found is the ResTek link below.
My write-up shows Methanol can be a safe choice, given our bodies produce it and we consume methanol daily through our diets. It took a home hobbyist to show how safe it can be? Fear shouldn’t a determining factor to perform tests, Scientific Observation and reporting should… You know there’s been years of doing this, where are the write-ups? There’s got to be more reports out there.
Oh, one intriguing question presents when reading the result of my tests. What happens if you do another stage #5 and sample? Will the PPM drop another 10x? Will a third stage #5 eliminate the Methanol altogether? Or will a 50ml volume of water/ethanol accomplish multiple stage #5 passes? My one take is that it didn’t matter if you used water or EoTH for the purge indicating the oil just needed more time to boil off the methanol. A better termination of stage #5 might result in sub PPM residuals.
All solvents up to a bp of 165C can be purged
To 0 ppm with not to much effort
Time heat and vacuum and defffanatly azeotrope boiling can get you there
Keep in mind that the USP guideline is actually based on a PDE of 30mg per day. That 3000 ppm is based on an “unknown” dosage of 10g.
Yes like i said earlier people were much too close minded in this thread. Three of the extractors I consider best in the game were using methanol for a long time and never failed for residual solvents. It has many great properties
Blockquote
Do you have any suggestions for the process? Is there anything that could be done better?
is there a difference with ethanol extraction except for the number of CH chain?
Defenatly methanol will extract less fats and waxes but more chlorofyl
Methanol is not considered as safe
Methanol needs less energy to evap off
Does not form an azeotrope with the picked up water from biomass
Easyier to re proof
